Dry-pipe valve



June-'12, 1928. 1,673,442

- E. E. CLARK DRY PIPE VALVE Filed Oct. 25 1924 Fig.1.

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Patented June 12, 1928.

EZRA n. CLARK, or NEw'ronvrLLn, nassacnosnrrs,

DRY-PIPE VALVE.

Application filed 0etober25, 1924. Serial No. 745,774.

This invention relates to dry pipe valves such as are used in so-called dry pipe sprinkler systems. In such springler systems the sprinkler pipes are filled with air under pressure and the flow of water to the sprinkler system is controlled by a dry pipe valve which is normally held closed by the pressure of the air in the system but which opens to allow water to flow into the system when the air pressure in the system falls be low a predetermined point by reason of air escaping from asprinklerhead which has given way or from any other cause.

When a sprinkler head in a drypipe systom opens by reason of a fire or otherwise the air in the system immediately begins to es cape and the air pressure begins to fall but an appreciable time interval will elapse before the pressure has fallen sufliciently to allow the dry pipe valveto trip. The length of such time interval will depend upon the volume of air in the system and, therefore,

, in a large system having the maximum numlift her of sprinkler heads allowed by insurance regulations the time interval between the giving way of a sprinkler head and the opening of the dry pipe valve will be greater than in the case of a small system having relatively few sprinkler heads. y

In the case of a fire itis, of course, important to have the water reach thesprinkler head which has given way with the least delay possible and in order to minimize this time interval there have been produced so.- called dry pipe valve accelerators which have for their object to accelerate the opening of the dry pipe valve after a sprinkler" head has given way. While these drypipe valve accelerators are effective in reducing the time interval between the giving way of a sprinkler head and the opening of the dry pipe valve, yet their installation involves considerable added expense, and introduces objectionable features. i i y A drypipe valve and the pipe connection and trimmings therefo constitute one of the expensive elements of a sprinkler system, and .for this reason it is customary to load each dry pipe valve with as large a number of" sprinkler heads as will be allowed by insurance regulations.

It is one of the objects of my present invention to provide a novel dry pipe valve which will accommodate the maximum number of sprinkler heads allowed by insurance regulations, but which will supply water at quickly than the usual dry pipe valve 'volved in installing a any head when said head opens much (more the samenumber of heads.

As one means towards accomplishing this for v end I use a dry pipe valve with a single inlet and with two separate outlets, which dry pipe valve is provided with a water valve "and a corresponding air valve for controlhug the flow of water through each outlet.

In using this dry pipe valve I propose to subdivide the portion of the sprinkler system to which the valve is connected, into sections of the system, but if a sprinkler head in either section glves way the corresponding reduction ofair pressure. in said section will resultinthe tripping of thecorresponding valve, thus allowing water to HOW to that section of the system in which is located the opened sprinkler head.

The two' sections into which the system.

controlled by the dry pipevalve is subditem on which the opened sprinkler head is located. By thus subdividing the system the volume of air in each section thereof is, of course, considerablyless than the volume in the entire portion of thesystem controlled Vided are independent from each other, so that the opening of a. sprinkler head :will i admit water to that portion .only'of the sysby the dry pipe valve and, therefore, the a time interval between the opening of the i sprinkler head and the tripping of the valve is correspondingly reduced." By means of my improved dry pipe valve the reduction in the timeinterval elapsing between the giving way of a sprinkler head and the ademitting of water to the system by opening the dry pipe valveis gained without the use i of a dry pipe accelerator and at an expense which is not materially greater than that in-,

commonly made.

Dry pipe sprinkler systems are usually installed in locations that are "subjected to freezing temperatures and an, advantage re" sulting from my invention is that when a sprinkler head opens the water will be admitted only 'tothattdivision of the system in which the open sprinkler head is located, thus avoiding the danger of having the entire system frozen upin cold weather, which exdry pipe valve as now ists where the water is admitted to those portions of a largegsystem remote from the,

opened sprinkler head and where there was no call for water. I As a further improvement, and to avoid water columning I vpropose to employ a valve structure for the water valve and airvalve', which is so constructed that. when surrounded by air it will be held to itsseat by gravity. But when the valve is near the critical trip ing point and the neutral chamber is filed u'p with water so thatthe valve structure is surrounded bywater, the position of the center of avity of the valve structure will change su eiently to bring it to a point at which thevalve will tend to i do a vision of the system only, the air pressure .valve. v

In order to give an understanding of the open b gravity. This change in the position o the center of gravity of the valve structure at the critical point facilitates the opening of the valve, so that the valve will open before a suiiicient amount of water-can pass by the air clapper to water column the maximum number allowed L by insurance regulations for-Yan y one dry pipeyalve.

In carrying out my inventlon I subd 1v1de theflsystem into two divisions andprovide a riser foreach division. Merely as an illustration ofthis', I have shown in F1 ,2

the. upper two s rinkler pipes 2 might-be those 0 the upper stories of a bu lding; connected to one riser 4* the lower two sprinkler pipes 2 which might, be those in the lowerstories of a' building, connected to the otherrise'r 4, .so, thatpartjof the sprinkleipi esare fed from. one riser and part from teother. f... f

My improved drypipe valve is rovided h a a s mmu icatin w th til water. supply system andwith two outlets communicating with the two risers 4 and 4, and it is soconstructed that if a sprinkler h e'ad in either .subdivisionfof the system gives way water will be admitted to that subdibeing retained in the other subdivision of the system. g p

The dry pip-e valve herein shown comprises a casing- 5 w 2 is a view illustrating an installation 3' system is normal.

ch has thesingleinlet 6 that is connected to a water supply pipe. This inlet is of the size required.by themaximum number of sprinkler heads to be supplied by the riser-s4 and 4.. Thetwo outlets of the dry pipe valve are indicated at 8, one being connected to each of the risers 4 and 4, as

stated above. The interior of the casing ,is divided intotwo chambers 9 and 10 and the inlet 6 is branched as shown at 11 and 12, one branch leading to each of the chainbers; The branches 11 and 12 terminate .in valve seats 13 la on which are seated water valves 15, 16. a

Each watervalve has associated with it an air valve, the latter being designated at 17 and 18 respectively. These air valves are pivotally mounted within the casing, the air valve ,17 eing pivoted at 19 and the air valve 18 being pivoted at 20. Situated within the chamber 9 is an annular valveseat 21 on which the air valve 17 seats and in the chamber 10 is a similarvalve seat 22 on which the airvalve 18 seats.

In the present embodiment of the l1'1V011-. tion the branches 11, 12 of the inlet diverge L from each other so that the water valvescats l3, 14 each have an angular relation. The

air valve seats 21,- 22 are parallel to the valve .seats 13 and 14 and, therefore, the water.

valve and air valve comprising each valve structure. are parallel to each other. Eachwater valvemay be connected to its air valve inany suitable'way as by means of a bolt; or screw 23.

The casing 5 is cg'vidcd by partitions'Ql, 25 to form a neutra chamber between each which is open to theatmosphere, these neutral chambers being designated at 26' and 27 respectively. j Each neutral chamber will shown asusual in dry pipe valves.

will be normally. closed and will be held closed by the pressure of the air againstthe air-valveso long as the air pressure in the But if,.for"instaince, a sprinlrlerhead in air in the subdivision of the system includmg said sprinkler head Wlll escape and when the pressure has been reduced to a predeter- In the operation of the device both valves -air valve and the corresponding water valve a 10. be provided with a suitable drip valve, not

.one of the sprinkler pipes 2" gives way the mined point the valve which is conncctedtod the riser 4* leadingto the sprinkler pipes 2 will trip, thus allowing water tofiow to the open sprinkler, head. The reduction of the pressure in the sprinkler pipes 2 will not, however, aliectj the pressure in the sprinkler pipes 2:30 that the water will only be delivered to that section ofthe system in which the open sprinkler, head is located.

The time interval required fora reduction of the air pressure. in the section 2 to a point where the valve will trip is very-much less than would be required to secure the same reduction of air pressure'throughout the entire system and as a result of this arrangement the time interval elapsing between the opening of a s rinkler head and the flow of water there rom is materially reduced, which is highly important in case of a fire. Moreover, since the opening of a sprinkler head will admit water to that section only of the system in which said sprinkler head is located there is no danger of a freeze-up occurring in cold weather in other sections of the system remote from the open sprinkler head and where water is not needed.

In the installation of a dry pipe valve the pipe connections and trimmings form a cost of installation of my improved duplex valve is substantially the same as that of an ordinary dry pipe valve.

As a further improvement in the dry pipe valve, I make provision for avoiding water columning of the valve-that is, the accumulation of water above the air clapper without the valve opening. This is accomplished by providing means for maintaining the center of gravity of the valve when surrounded by air, on the valve side of the pivot about which valve swings and for shiftin this center of gravity to the other side 0? pivot when valve is entirely surrounded by water, which would be the case when the valve is near the tripping point.

This shifting of the center of gravity may be accomplished in various ways. The selected way as shown herein is to form a chamber in the air clapper and fill the same with a substance having substantially the same specific gravity as water.

When the valve is set ready for operation the space immediately above the air clapper contains priming water, while the neutral space below the air clapper is filled with air at atmospheric pressure. When the pressure in the system is reduced to substantially the point at which the air valve will trip, then the valve structure will begin to flutter and water will accumulate in the neutral chamber, so that at the time the valve trips there is water in the neutral chamber and the air valve has water on both sides thereof.

The chamber in the air valve which is filled with this material having substantially the same specific gravity as water, is so located that under normal working conditions when the neutral chamber is filled with air the center of gravity of the valve structure will be on the side of the pivot toward the valve seat, and the action of gravity therefore will tend to hold the valve seated. When the critical tripping point is about reached and the neutral chamber is filled with water, then because of the fact that the material in the chamber of the valve has substantially the same specific gravity as water, said material willcease to have any valve-closing eifect, and as aresult the center of gravity of the valve willshitt to the opposite side of the pivot. i

Referring to the drawings it will be noted that the air valve 18 provided with a chamber 32 which is filled with some material 31 such, for instance, as a suitable wax,

that has substantially the same specific gravlty as water. The valve structure 18 j i withoutthe material 31 is so designed that the center of gravity thereof is at the right of the pivot 20, and, hence it the material 81 were removed from the chamber the valve would tend to open by gravity.

So long as the neutral chamber 27 is filled I with air, so that the valve 18 has water on 1 its upper side only, the material 31 adds its weight to the weight of thevalve 18, tending to hold the valve closed, and under these conditions the centerv of gravity of the combined air and water valve will beat the left of the pivot 20, so that the action of gravity tends to hold the valve closed.

, When, however, the air and water valve 1 structure is entirely immersed or submerged in water ora pressure having the same specific gravity as that of the material 31, which will be the condition when the valve structure is about totrip and the neutral chamber 27 is filled with water, then the material 31 ceases to act as a weight, because it has substantially the same specific gravity as water, and the efi'ect is the same as itthe material 31 had been removed from the chamber 32. y I a y Therefore, under the conditions the cen ter of gravity is shifted to the right of the pivot 20 and the valve tends to open by gravity. This construction, therefore, fa-

cilitates the opening movementof the valve tween the giving way of a sprinkler head and the flow of water therefrom without materially increasing the cost of installation and I have further improved the valve by providing novel means for 'avoidingthe water columning thereof.

I claim: i

p 1. A duplexdry pipe valve comprising a casing divided into two chambers each hav ing its own outlet, said casing having a single inlet which is branched with one branch leading to each chamber, a separate water valve for closing each branch, an air valve for each water valve,each air valve being subjected only to the air pressurein the corresponding valve chamber and operating to hold the corresponding" Water valve closed, said easing having t svo separate neutral chambers, one between each water valve seat and the corresponding air valve seat. 3 i I 2. In a dry pipe valve, a casing having a waterway and a valve structure adapted to close the waterway and comprising a water valve and an air valve, there being a neutral chamber between said valves, said valve structure being so constructed that the action of gravity thereon will tend to hold it closed \vhenlhe, neutral chamber isfilled with air and will tend to open it when said chamber I e 'valvestructure that when the neutral chem ber is' fillell'with eir the action of gravilzv on the valvestrnctiire fends'to hold it "closeil while when said ch ajrnber'i's filled l with water i thecenter of gravity ofthe vulVeiS shifted to al point 'at which theaetiolrof; gravity tends to open the valve structure- 4. In a dry pipe va'lvqlhe eomlnnatmn with a casing having a Waterway, of a Wiltfif valve to close saidwaterway, '51 pi'votellyi mounted air valve fo holcl the water valve closed, said casing having a neutral ehiiinf her between said vlve'," said air \"qlve having a poeket filledivilh material having substnn Lially" the smile specific ',az ra vilfy asWvatr,

whereby when thevalve structure is entirely itvof the valvegwill shift froi'li position in wh ch the action'of gravity tendslh "hold action tends to open the valve;

the valve closed To a position-in whiclrsaicl all , surrounded with water hy 1feason of the neu-f' trel chefinh'er being filled; the center: of gr:iv'-"" In test-imony whereof, I have signed 'n'iy' name to this specifiea'tien';

l ,E RKE ARK 

